FXUS63 KABR 111733

Area Forecast Discussion
National Weather Service Aberdeen SD
1133 AM CST Mon Dec 11 2023


- After some cooler temperatures on Tuesday, high temperatures will
run between 5 and 15 degrees above normal this week (normal highs
are in upper 20s and lower 30s). Near record warmth on Thursday,
with highs in the upper 40s to low 50s (15-25 degrees above normal).

- Southwest downslope winds are expected on the east side of the
Prairie Coteau Wednesday night through Thursday morning, with a 60-
80% chance of winds greater than 40 mph.


Issued at 1132 AM CST Mon Dec 11 2023

No significant changes have been made to the ongoing forecast. We
still have the slight chance (15% chance) of light snow possible
this afternoon over northern portions of the forecast area thanks
to the cold front.


.SHORT TERM /Today through Tuesday Afternoon/...
Issued at 310 AM CST Mon Dec 11 2023

Weak upper level ridging will give way to a more consistent
northwest flow on the southwest side of a trough tracking from
central Canada to Hudson Bay.

At the surface, the trough associated with the upper trough will
drag a cold front across the CWA today. Cannot rule out some light
precipitation along the front, mainly across the northern CWA.
Chances look pretty low however, generally in the 15-20% range. Will
also see some breezy northwest winds behind the front, with gusts in
the 20 to 30 mph range this afternoon into the evening hours. High
pressure then settles in behind the exiting front tonight, bringing
lighter winds and some pretty chilly nighttime temperatures to the
area. The high will remain dominant over the area on Tuesday, but
does look to just begin to start an eastward trek later in the
afternoon. This pattern will continue to keep cooler temperatures
over the area on Tuesday as well. Other than the small chance for
precipitation today, the short term period will be dry.

High temperatures today will range from the lower to mid 30s across
west central Minnesota and far northeastern South Dakota, to the
upper 40s across south central South Dakota. Low temperatures
tonight will generally be in the 10 to 15 degree range. Highs on
Tuesday will range from the lower 20s along the Prairie Coteau, to
the mid 30s across south central South Dakota.


.LONG TERM /Tuesday Evening through Sunday/...
Issued at 310 AM CST Mon Dec 11 2023

A zoomed out look at the overall flow pattern between Tuesday night
and Sunday shows generally a positive PNA pattern, with predominant
upper ridging over the western CONUS and troughiness over the
eastern CONUS (northwest flow over this CWA). Models prog a period
from Wednesday through Thursday when upper ridging will propagate
west to east across NOAM, but then resets to ridging in the west and
troughing in the east heading into the weekend.

This pattern is very supportive of the ongoing dry weather forecast.
Still monitoring the potential for a couple of downslope wind events
this week during times of low level WAA, with the most pronounced-
looking scenario being in that late Wednesday night through Thursday
timeframe. With the majority of steering flow winds being either
well to the south (southern plains/deep south) or shunted off to the
north, looking at just a couple of cold fropas during the extended;
the first progged for Thursday night into Friday, with a second
fropa lined up right now for Saturday night. But, these periods of
post-frontal low level CAA are not expected to last very long, only
interrupting low level WAA for, perhaps 12 to 18 hours in each
instance. The general consensus of things being warm (warmer than
climo normal) in the out periods still suffices.


.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1132 AM CST Mon Dec 11 2023


VFR ceilings and visibility can be expected through the next 24
hours, along with a non-diurnal wind that remains elevated with
gusts around 20 mph through around 02Z at our western locations
(MBG/PIR), 09Z at ABR, and 11Z at ATY as high pressure builds in
from west to east tonight.